Liam shackleton



July 3, 1928. 1,675,410 JVH. GARTNER PRESSURE INDICATlNG DEVICE Filed Feb. 15, 1927 2 Sheets-Sheet 1 ulllll/Irz 11/ I ll INVENTOR Jaw/v 6A1? 7W5 yaw ATTORNEYS.

July 3, 192a. 7 1,675,410

J. H. GARTNER PRES SURE INDICATING DEVICE Filed Feb. 15, 1927 2 Sheets-Sheet 2 may INVENTOR Jay/v IV. 614/? TNER Mal ATTORNEYS.

Patented July 3, 1928.

UNITED STATES PATENT OFFICE.

JOHN H. GARTNER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR OF ONE-FIFTH TO PATRICK S. HIGGINS, ONE-FIFTH TO JAMES D. SKELLY, AND ONE-FIFTH TO WIL- LIAM SHACKLETON.

PRESSURE-IN DICATIN G DEVICE.

Application filed February 15, 1927. Serial No. 168,373.

7 of a motor vehicle while the vehicle is in motion. It is particularly proposed to arrange, for this purpose a series of lamps in such a manner that one or more of them l ght when p the pressure in oneior more tires changesffrom normal beyond a predetermined degree. y

It is further proposed to provide a novel switch arrangement causing a lamp assigned to a particular tire to become active when the said tire is either under or over nflated.

It is further proposedto subject one of the elements ofthe switch mechanism to the direct action of the pressure within the tire.

It is further proposed to provide a sw tch arrangement of the character described, one

part of which is secured relat ve'to the vehicle frame while the other part is secured relative to the wheel and revolves with the same. It is further proposed to provide a switch mechanism that under these circumstances makes a smooth continued wiping contact and is noiseless and little subject to wear.

. Further objects and advantages. of my invention will appear as the specification proceeds. The preferred form of my invention is llustrated in the accompanying drawlng, 111 which v.

Figure 1 shows a vertical section through a wheel and adjacent portions of a motor vehicle with my pressure actuated switch mechanism secured thereto;

Figure 2 an enlarged detail view of the switch mechanism viewedas in Figure 1;

40 V Figure 3 a rear view of the actuating mechanism for the movable switch member;

Figure 4; a front view thereof;

Figure 5 a vertical section through the same as viewed from line 55 of Figure 4; I Figure 6 a view of the switch mechanism as seen from line 6 6 of Figure 1;

Figure .7 a sectional detail view of a joint interposed between the ordinary valve and the actuating means for my switch mechanism;

Figure 8 a view illustrating the arrangement of lamps adapted to give various indications relative to the pressure in the tire; and

Figure 9 a wiring diagram.

Vhile I have shown only the preferred form of the invention, it should be understood that variouschanges or modifications may be made within the scope of the claims hereto attached without departing from the spirit of the invention.

The wheel 1 of a motor vehicle may be constructed in any suitable manner and is provided with a tire 2, and an inner tube 3 adapted to be inflated through a valve at of conventional construction. For the purpose of the presentinvention it is assumed that the wheel has a brake drum 6 fixed thereto, it being understood, however, that thebrake drum does not form a necessary part of the invention, since any other supporting ele ment may serve the same purpose. Fixed to the outer face of the brake drum by means of screws 6 is a cylinder 7 shown in detail in Figure 5, the cylinder being closed at one end as at 8 and having a piston 9 reciprocably mounted therein, a spring 11 being interposed between the end 8 and one end of the piston, while the opposite end of the piston is formed with a pocket 12 into which is introduced a rubber cup 13 bearing against the inner face of the cylinder and forming an airtight seal when subjected to a pressure of the tire through the perforated cap 14 communicating with the valve 4. In order to allow of free communication between the tube 3 and the upper faceof the piston 9 I remove the conventional Schrader valve and introduce what is known as Schraders universal connection illustrated in detail in Figure 7, providing a short tube 16 adapted to be fastened to the valve 4 by means of a coupling 17, and provided with a lateral arm 18 into which a conventional valve, not shown, may be introduced. The lower end of the tube 16 may be connected to the upper end of the cylinder 7 through a flexible tube 19. V

It will be seen that the position ofthe piston 9 within the cylinder 7 indicates the pressure within the tire and a pointer 19 extends laterally from the piston through a slot 20 in the cylinder wall, which latter is provided with a suitable scale 21 allowing the pressure to be read. When the pressure is loW the pointer .19 Will be ina position as shown in Figures l: and 5, and vvhen the pressure increasesto normal the piston will compressthe spring 11 and move to the mid- 1 die of the slot. As the pressure increases beyqeli ne tmel he Pi to moves low i r fsrtl rand-tl e p in r 19 mov s to h bottom of the slot, it being assumed for the purpose of the present description that a pressure Off'tQ-SttlIlClS for normal, of 34 for low andof 50 for high. 7

A second element or arm 22 extends from the pis'ton in the'oppositedirection and is subject to the action of the pressure Within 40 I a 36, the same being supported on short posts shoes to be insulated from the-housing Thet 'vo semi-circular contacts are mounted so a's tobe'straddled by the two prongs 26 and "27"of the'yokeQand to be normally cleared b j'the spri g .contactsgl 211K132 u 'y the er When the'yoke moves radially in one direction or the other in'response to changes in tire pressure The operation of the unit thus far described Will be readily understood I from the I foregoingdescription.

TheupperViace of the piston 9 is directly the" ti re and occupies normally a'midvvay position so that thepointer 19'is substanf l tially -in themiddleof the slot 20, opposite the' 'letter N. V r V Asllongas the "piston occupies this'posr tion theyoke and'the' spring contacts thereof clear the stationary contacts 34; and 36. But when the'pressure in the tirechanges, either increasing or decreasing the-piston moves radially 1n one direct on or theother, 'causing the yoke to*m0ve correspondingly and causing e ther the upper spring contacts or th-e'lotver spring contacts to successively engage the two are shaped contacts 34 and 36,

according to the intensity of the change. If

there is,for-instance; a slight increase the spring contact lengages the semi-circular contact 34 and when the pressure further -inc'r'eases the second spring contact 32 vongages the arm 36, "Correspondingly on a decrease otpresjs ure the arms 32- 31 of thej lo'vveri prong 'of-lthe' yoke successively ngage the stationary contacts 136 and 34;

l liesiv tch mechanism here nabove described may be utilized for giving the alarm signals in the manner illust'rated'in the Wiring diagram of Figure 9, in Which one central lamp 4:1 is surrounded by. four lamps 42; Assuming that the four spring contacts 31' '32 are grounded, that the stationary contact 3% ofeach Wheel is connected through the Wire 34, through the central light 41 to the battery 43 and the grounds e and that the st ti na y cont 36 of the four Wheels are conneoted through wires 36 vandithe four lamps 42 respec tively to the battery 43 and the ground, the

operation will be as' iolloWs :fl/Vhen the yoke 7 moves centervvise in response to increasein pressure the upper two'spring contacts 31 and 32 successively" engage the stationary j'contactsge and 56, first "lighting" the central 7 lamp 41; thereby advising the" driver that oneormore' tires are'oveninfiated' and then lighting one or the lamps 42, thereby iniorining thedriverwhich particular oneor the tires isover-inflated, 'and 'also indicatingthatf we ver-nuances so intense as to'be dangerous If the yoke moves" outwardly in response to lack of-pressurezthe two lower yingconmete '32'and: 31 sllQGessively engage the vvires 36' and 34', the first engagemeht lighting onejof the lights 4:2, thereby informingthe driver "that-oneofT the tires is under-inflated; and also identi- '1"tyi ng the tire, While the[second engagement informs the driver'that -the tire issubstan- 'tially It Willbe noted that the 8110- cession is reversed for under inflation, "so that .the driver may ascertain from p the sequence of the operation Whether, the tire in vquestion under'i'or over inflated 1. In meansior indicating the pressure in the tire of a moving vehicle, an arc-shaped contact fixed ename the vehicle adjacent a Wheel'thereof, a Wiping Contact supported relative :to the wheel and operating means iorthe iping cont-act subject to thepressnre 'in-the' tire and arrangedtokeep the latter contact'spaced from the former" at normal tire pressure, and toefi'ect 'engagement of the contacts i'vhen the tirefpressure' changes beyond a predetermined poi-nu '2. In means'foriiidicating the pressure in the tire of a moving vehicle; anfar'c-shaped contact fined relative-tothe vehiclead jacent a wheel thereoi 'a Wiping contact supported relativetothe Wheel; a radial cylinder havmeans for subjectingthe'pistonto theac- 'tion 'ofth e pressure Within the 'tire and an operative connection between "the 'pistonfand the Wiping contactcausing the latter to' engage the arc-shaped conta'ctwhen'the pressure in the'tire'is other'thannormall" 3. In means for indicating the pressure in the'tire of a moving vehicle, 'an' arc shaped contact fixed relative to the vehicle adjacent awvheel thereof} a yoke supported relative to the. Wheel to straddle the arc-shaped con .ing *a piston resiliently movable therein,

tact and having wiping contacts above and below the former contact, a cylinder on the wheel having a piston resiliently mounted therein, means for subjecting the piston to the pressure within the tire causing the piston to move in response to changes in the tire pressure and an operative connection between the piston and the yoke causing the latter to move with the former for operating the wiping contacts.

4. In means for indicating the pressure in the tire of a moving vehicle, two parallel arcshap ed contacts fixed relative to the Vehicle adjacent a wheel thereof, a yoke supported relative to the wheel to straddle the areshaped contacts having wiping contacts for each of the arc-shaped contacts below and above the same, means for operating the yoke in response to changes in tire pressure for engaging either the lower or the upper wiping contacts with the arc-shaped contacts, the upper and the lower contacts being clifferently spaced from the arc-shaped contact to become active at different tire pressures.

5. In means for indicating the pressure in the tire of a moving vehicle, an arc-shaped contact fixed relative to the vehicle adjacent a Wheel thereof, a wiping contact supported relative to the wheel and means for operating the latter is response to changes in tire pressure for engaging the former when the tire pressure departs from normal.

JOHN H. GARTNER. 

